关键词: GaNHEMT, 宽带, 内匹配, Lange桥

Abstract: A design method for an S-band balanced power amplifier is proposed, and research work including the design of internal matching circuits, power combining, and testing has been carried out. The RF parameters of GaN high-electron-mobility transistor (HEMT) devices are determined using a load-pull system to achieve high-power, high-efficiency impedance matching. The matching circuits are fabricated on high-permittivity dielectric substrates and integrated with GaN technology to realize miniaturization and high performance of the amplifier. Under operating conditions with a drain voltage of 43 V, pulse width of 100 μs, duty cycle of 15%, and frequency range of 2.7-3.5 GHz, the measured circuit performance is improved through asymmetric tuning techniques applied to symmetric circuits, in conjunction with matching circuit simulation results. The Lange coupler port impedance is also precisely simulated and designed. The in-band pulse output power exceeds 350 W, with a maximum output power reaching 389 W, a power-added efficiency (PAE) greater than 62.5%, and a peak PAE of 69%. The high efficiency and low thermal dissipation demonstrate the reliability of this high-power amplifier under high voltage.

Key words: GaN HEMT, broadband, internal matching, Lange coupler